1. Field
This invention generally relates to systems and methods for detecting image quality defects generated by a rendering device.
2. Related Art
Image rendering devices such as photocopiers, printers, facsimile machines, and other image producing devices, have been widely used in commerce and industry. Computing devices have also been widely used in commerce and industry. Higher demand for these computing devices has resulted in faster processing speeds that are sufficient for electronically detecting defects in the images rendered by image rendering devices. Detection of image quality defects ensures the production of quality images by image rendering devices.
There are various existing approaches for detecting image quality defects in images rendered by image rendering devices. For example, in order to detect image quality defects, images rendered by an image rendering device, such as a printer, are captured by an image capturing device, such as a camera, a scanner, or the like, are compared with synthetic models of an ideal scene, e.g., a standard test page designed to provide information about the performance of the printer, to detect the existence of an artifact or defect in the image. Further, U.S. Pat. No. 6,377,758 describes a method and a system for analyzing imaging problems by printing an image, scanning the printed image and comparing the scanned image and the original image on a pixel by pixel basis to detect defects generated by an intermediate imaging member.
Although some image quality defects may not be visible, these image quality defects may indicate that the device is deteriorating, and presage image quality defects that are visible. Other image quality defects may be largely of a geometric nature and caused by distortion due to slight warping of the rendered image, small misalignment of the captured image, mapping errors between the image capture device and the image rendering device, and other systematic defects of the image rendering devices not related to degradation of the rendering device. Therefore, it would be desirable to detect the image quality defects early, so the image rendering device may be adjusted or repaired to reduce or even avoid image quality defects. Furthermore, it is desirable to detect only the image quality defects that are either visible or presage visible errors.